Delay and regulating valve



June 4, 1957 P. F. SWENSON DELAY AND REGULATING VALVE Filed Aug. 19, 1954 INVENTOR.

Paul K Jwemson DELAY AND REGULATING VALVE Paul F. Swenson, Cleveland Heights, Ohio, assignor to Iron Fireman Manufacturing Company, a corporation of Oregon Application August 19, 1954, Serial No. 450,916

Claims. (Cl. 137-491) This invention relates generally to fluid control valves and more particularly to fluid pressure regulating valves. The invention has for its principal object the provision of a valve adapted to be inserted in the main steam line between a low pressure heating boiler and its load for the purpose of isolating the boiler from the load when the boiler pressure is below a pre-set load pressure and for regulating the supply of steam to the load by the boiler to maintain the pre-set load pressure when the boiler pressure is above the pre-set load pressure.

It should be understood that in a modern low pressure heating system the boiler may be fired by an onoff type of fluid fuel burner which uses the heat storage capacity of the boiler to prevent too frequent operations of the burner. To utilize this feature of the boiler the burner operations will be controlled by a boiler pressure control set with such wide limits of, say, a low of six pounds to a high of twelve pounds, while the load may be designed to operate best at a uniformly held pressure preset at the load pressure regulating valve at, say, three pounds per square inch gauge pressure.

If, in a system of this type having load steam lines and load steam convectors for space heating of small volumetric capacity, when the boiler is started up and starts to generate steam, this very wet steam at low pressure is allowed to enter the load lines the steam will first fill the load system with condensate water which may damage the system when the steam pressure rises to a pressure which will force circulation of the condensate.

To prevent this undesirable operation of the system the valve of the present invention has the unique and useful ability to remain closed until the boiler pressure has built up to the pre-set design load pressure and then to open to supply steam to the load. Thereafter while the boiler pressure is above the pre-set design load pressure the valve of this invention will operate to pass just enough steam to the load to maintain at the load side the pre-set design load pressure.

To accomplish this result it is a second object to provide a device having a main valve adapted to use the main steam supply at boiler pressure to open the valve and pressure from the same source to provide a valve closing force in substantial balance with the valve opening force.

It is a third object to provide in the device means responsive to the pressure on the load side of the device for reducing the valve closing force on the main valve to allow the main valve to be opened as required to maintain the pre-set design load pressure.

How these and other objects areattained is explained in the following description of a preferred form of the valve of this invention referring to the single figure of the drawing which shows the valve in vertical center plane section.

Referring now to the drawing it is seen that the delay and regulating valve of this invention has a hollow main body casting 11 the interior of which is divided by parti- States Patent Q E Patented June 4, 1957 tion 12 into an inlet space 13 and an outlet space 14. Threaded opening 15 into space 13 is adapted to receive a steam pipe from a source of steam and threaded opening 16 into space 14 is adapted to receive a steam pipe leading to a load. Body 11 is formed with a downwardly extending hollow collar 17 open at its lower end and opening into space 14 with the axis of collar 17 intersecting at right angles the axis of inlet and outlet openings 15 and 16.

Formed axially with collar 17 in partition 12 is a threaded main valve port with valve seat 18 threadedly secured therein.

Internally threaded union nut 78 adapted threadedly to engage externally threaded collar 17 secures therebetween pilot valve seat body 19 and delay valve seat body- 26 both formed to provide annular passage 21 divided by perforated washer 22. Passageway 23 in body 19 and passageway 24 in body 20 connect threaded hole 25 in body 19 through perforations 26 in washer 22 with threaded hole 27 in body 20. Delay valve seat screw 28 threaded into hole 27 in delay valve seat body 20 is reduced in outer diameter at 29 to form an annular passage therearound open to hole 24. Transverse hole 32 formed through screw 28 connects passage 29 with axial hole formed upwardly through screw 28. The upper end of screw 28 surrounding hole 38 forms the delay valve seat 31. Holes formed in delay valve plate 33 fit loosely over pilot valve stem 34 and guide pin 35 secured into body 20.

Hermetically sealed to pilot valve seat body 19 is flexible metallic main valve bellows 36 sealed at its upper end to head 37 formed with a central hole therethrough into which is threaded cup 38 open at its upper end and formed with central hole 39 through its base. Main valve 40 is clamped between cup 38 and head 37. Metal tube 41 threaded into hole 25 in body 19 extends axially with fluid flow clearance through hole 36 in cup 38 to the interior thereof. Cap 42 with a central hole therelthrough secures wire screen 43 and orifice disk 44 over the top of cup 38. Orifice 45 in disk 44 is a critical element of this invention.

Pilot valve seat 46 with passageway 47 connects valve body space 14 with pilot valve chamber 48.

Cylindrical plug 49 threaded into cylinder 50 and sealed thereto by gasket 51 has sealed thereon pilot valve bellows 52 sealed at its top end with disk 53 having cup 54 axially sealed therein. Cylinder 50 is threaded onto body 20 and sealed thereto by gasket 63. Pilot valve stem 34 headed at its upper end to form pilot valve 55 passes downwardly through delay valve 33 and axial hole 56 in body 20 and is then threaded into cup 54. Hole 56 provides fluid flow clearance around stem 34.

Guided on cup 54 at its upper end and a central boss formed on adjusting screw plug 57 at its lower end is pilot valve closing spring 58 proportioned to be adjust: able by screw 5'7 to determine the pre-set design load pressure of the system. The interior of bellows 52 is open to atmosphere through central hole formed in adjusting screw 57.

The operation of the device is as follows. Note that in the position of the parts showing in the drawing the pressure at the load is up to its pre-set design value and the boiler pressure is at least above the load pressure. The back pressure in space 14 through passage 47, pilot valve seat 46, valve chamber 48, hole 56 and into space 59 within cylinder 50, has compressed bellows 52 and load pressure spring 58 to hold pilot valve 55 away from its seat 46 and delay valve 33 onto its seat 31 thus equalizing the pressure within the main bellows 36 with that in the inlet space 13 and allowing the small biasing force of the resilient metal of which bellows 36 is formed to close main valve 40 onto its seat 18. It should also 3v be. noted that the average internal diameter of bellows 36 is slightly greater than the diameter of valve 40 at its contact circle with seat 18 so that with balanced pressure irrther spacesilfi and 6 1: the closing: force; on the", main valvewill be siightly greater than theopeningforces New assuming: that the system: is: entirely shutdown with. no pressure inespace: 13; their the=main valve 40:1 8- willbeclosed; spring-% will have closed the pilot valve 55 -46? and; the delay: valve-33 loosely guided on pin 35* and stem 3r4 will; be resting of its own: weight on delay valve. seat-3:12 Then assumeithat the" system is started up'by energizing the boiler burner'and putting-it under control of its boileri pressure control. The boiler will get warm; then hot, and-form; steam: at. regularly; increasing: pressure which prQSSure-willbe communicated to space 13; to the interior of cup3.&throughiorifice 45, to the space 61' through hole 39! and tO iHlEIiOI-ZOfthe lower end: cylinderSO- through tube 41', passagewayslfi', 24,. 321 and 302 to lift valve 33 and enter chamber 48* then down through hole56;

' As the: boiler pressure'rises the pressure on' bellows 52 increases-and; the: bias of spring38; on pilot valve 56 is gradually overcome until at the; load' design pressure preset byrthe'adjustmentr ofscrew 57- pilot valve 55 separates from its seatf46 and the pressure of fluid in space'61 is suddenly released to space 14' through'hole 39, tube'4l, hole' 25, passageway 23', perforations 26in gasket 22 in annular passageway 21, passageway 24, clearance 29, holes 32; 30,, delay valve 31; 33; chamber 48 and pilot valve 55, 46. Although steam under. pressure in space 13 is at the same time attempting to make up the loss in pressure in 'space: 61, orifice 45 is too small to-a1low for rapid makeup a'ndthe reduced pressure in space 61 allows-thepressure in space 13-to open: the main valve 40 -18 anddischarge steamdirectly through the main valvefrom space 13 to space 14:

This sudden-reduction of pressure in-space 61 also'reduces the pressure within cylinder 50 and pilotvalve 5'5;46-may'c1ose unless-the back pressure in space 14 caused by the rush of steam through the main valve is sufiicient to back'into chamber 14' and down through holez56 and holdzthe'pilot valve open. But-should the pilot valve 5546 close to allow the pressure in-space 61 to build-up. through orifice-45 to. give closing pressure suflicient to close the main-valve the pressurein space 13 willragain' build up as before, be communicated" to space: 61 and through: the route above. explained to the interior of cylinder 50 and the pilot valve will again open torrepeatzthe reductioniofwpressure in space 61 and the opening of main valve 40-18. This repeated operation will in-tarverry. short timewhile thesteam pressure-inthe boilenis increasing fillsthe load side withstearn up to the pressurerrequired. in space 14 to hold the pilotvalve 55-46 open so that space 61 will be continuously at a reducedapressures and keep the, main valve open.

Then .when the load side of the system is hot and the. pressure space14v rises above the pre-set load design limit thebackpressure from space 14 and the wiredraw-n pressure from space 61 will build up in the interior ofcylinder 50 .andi pilot. valve.5546 will be fully opened and delay valve 31-33 will be held closed by the head onipilot valvestem34 and pressure will buildup in space 6Ltosclosethemain.valve as shown in the. drawing,

In operation. it iSseentherefOre'that the back. pressure fronrspace. 114, orthe load pressure, is continuously regulated 'to the. pressure pre-set by the adjustment ofscrew 57.1 In practiceit islfound that with a supply pressure varying-,fromra low of. about six pounds to a high of about 12, pounds. the loadpressure is held to a variation of about one; tenth of a poundwith thisdevice. A share. ofi this-good" result is obtained through they dash: pot action which is inherentlintthe device andwhich' keeps it from toorapid. alternate action or hunting.

This dash pot'type influence adaptedtothedamping of'the operations ofthe valves 'in' the present device is the actuation controlling fluids to and from the spaces in which the fluids are eflective.

The main valve operation is effected by fluid admitted to or emitted from space 61 through passage 39 and for operation of the pilot valve fluid must be transferred to or from the space within cylinder 50 through the passageway 56. In the design illustrated the desired-damping of the valve actions is assisted when steam is the fluid to-be controlled by the collection of condensate Withinthe valve operating parts. Ih'operation with'steam, condensate will normally condense and fill the spaces 61, 48, the space in cup 38' to'a" level approximatelyat: the-top of tube 41, the space within cylinder 50, and the passageways connecting these spaces. The operating pressures and fluid motions continue to operate on the valve as previously described but with water in the spaces and passageways all the valveoperations areeffectively clamped in the structure shown,

Having; thus stated some ofthe objects of my. inven-- tion, illustrated and described a: preferred form in; which my invention can be practiced and explained its operation; I desiretohold-for myselfthe exclusive right-to the form shown and-the equivalents thereof and I claim.

1. A: fluid'flowdelay and regulating valve device comprising a--mainva1ve,; a first pilotvalve, a second pilot valve, means adapted-to open said main valve when said" pilot valves are open and adapted to close said main valve will open 'to co'nneet said third-space through said fifth when either of-said pilot valvesare closed together with means responsive to the pressure at the outlet of said valve device to control the operation of saidpilot valves when said=first pilot valve is open=and responsiveto the pressure at the inlet of said: valve device to control the operation of said pilot valves when said first pilot valve isv closed and said' second pilot valve is open, said pressure responsivepilot valve controlling means including adjustable resilient meansv adapted to be pre-setto govern the pressures atwhich said p'ilot valves respectively will be closed.

21 The device of? claim 1 including meansadapted to damp the-operation of all'of' said valves.

3. A fluid flow delay and regulatingvalve device cornprisingmeansforming a main. fluid conduit through said device, a partition adapted to divide said conduit into an inlet space andan outlet. space, a main valve port formed throughsaid'partition, -a main valve for saidmain valve port, a first resilient means adapted to bias said main valve toward its position ofclosure of said main valve port, means including said resilient means adapted to enclose a third space, means adapted to enclose a fourth space, one wall of said fourth space having an o'rlfibe' formed therethro'u'ghconnecting said inlet space with said fourth space, a secondwallof'said fourthspace' having a" hole formed therethrough connecting said third space port formed therein, another'wall of said'fifth space hav-- ing a pilot valvepiortform'ed therein; a delay valve for said delay valve'port; a pilotvalvefor said pilot valve port, pilot'fluid condnitmeansconnecting said-delay valve port'with' said fourth-space and said pilot valve port with said outlet space,' a second resilient means adapted" ad justably to bias; said' pilot" valve toward itsposition of closure of saidipilot'valvepon, means adapted to form a sixthsp'ace; meansinsaidsixth space adapted-to oppose the'biasi'ng forceof said second biasing meanson said pilot valve andadaptedto-close' saiddelay valve -on'- its port'at a pressurein said 'siirth space 'greater'thanthe pressure'required to lift' sa'idpilbt valve from' its port; whereby when-no fluid-"pressureis in l said' main fluid con duit said main -valve-will he'clo'sed by saidflr'st resilient" means and said pilot valve will be closed by said second resilientmeans and when afluid'pressure is built upto: a predetermined value" in 1 said' inlet spacesaid pilotvalve:

space and said fourth space to said outlet space to allow said pressure in said inlet space to open said main valve to connect said outlet space with said inlet space and thereafter when the pressure in said outlet space said fifth space and said sixth space is built up to said pre-determined value said opposing means in said sixth space will close said delay valve to leave said third space in communication only with said inlet space through said fourth space and the pressure of said inlet space in said third space will close said main valve. v i

A. The device of claim 2 in which said third, fourth and fifth spaces are liquid filled. V

5. A pilot valve controlled main fluid delay and pressure regulating valve including a main valve, a pilot valve, a delay valve, means adapted to open said main valve when both said pilot valve and said delay valve are open and to close said main valve when either said pilot valve 'or said delay valve is closed, and means adapted to hold said pilot valve closed when the fluid having passed said main valve is below a first pre-set pressure, to hold said delay valve closed when said fluid is above a second preset pressure and to open both said pilot valve and said delay valve when said fluid is between said pre-set pressures.

6. The device of claim 4 in which the opening force for said main valve is produced by the direct application of the pressure of the fluid supplied to the inlet of said device, in which the closing force for said main valve includes the pressure of the fluid in a chamber separated from said inlet by a small orifice, and in which the pressure of the fluid in said chamber is controlled by means responsive to the pressure of the fluid passed through the device to the outlet thereof.

7. The device of claim 5 in which the means responsive to the pressure of the fluid passed through the device includes a fluid conducting passageway independent of said main valve from said chamber to said outlet, said pilot and delay valves being non-overlappingly serially connected in said passageway and in which the means for holding said pilot and delay valves is responsive to the pressure of fluid in said passageway between said pilot and delay valves.

8. The device of claim 6 in which said means responsive to the pressure of the fluid at the outlet of the device includes adjustable resilient means adapted to bias said one of said pair of valves toward its open position and to release said other of said pair of valves for opening of said other of said pair of valves by the pressure of fluid in said passageway from said chamber to said other of said valves and means adapted to oppose said biasing means by the outlet pressure of the device when said one of said pair of valves is open and by the pressure in said passageway from said chamber when the other of said pair of valves is open.

9. The device of claim 4 including means for damping the actions of all said valve opening and closing means.

10. A fluid flow delay and pressure regulating valve comprising a hollow main valve body formed with a rigid partition across the interior thereof to divide said interior into an inlet chamber with an inlet port formed through a wall thereof and a second chamber, said rigid partition having a main valve port formed therethrough with a main valve seat formed around said main valve port on the second chamber side of said partition, a resilient partition dividing said second chamber into a main valve op- 6 erating chamber and an outlet chamber having an outlet port formed through a wall thereof, said resilient partition including a main valve adapted to be closed on said main valve seat by said resilient partition when the pressure in said main valve operating chamber is above a preset ratio to the pressure in said inlet chamber, a small orifice formed through said resilient partition connecting said main valve operating chamber to said inlet chamber, means forming a pilot valve chamber having a first pilot valve seat and a second pilot valve seat formed on the wall thereof, fluid conduit means connecting said outlet chamber to said pilot valve chamber through said first pilot valve seat, fluid conduit means connecting said main valve operating chamber to said pilot valve chamber through said second pilot valve seat, means forming a pilot pressure chamber connected with said pilot valve chamber, a pilot valve stem extending into said pilot valve chamber :from said pilot pressure chamber, a first pilot valve and a second pilot valve operable by said valve stem in said pilot valve chamber alternately to close said first pilot valve on said first pilot valve seat and said second pilot valve on said second pilot valve seat, a resilient wall in said pilot pressure chamber, said valve stem being secured at one end to the inside of said resilient wall, adjustable means biasing said resilient wall inwardly of said pilot pressure chamber, and said resilient wall being biased outwardly by the fluid pressure in said pilot valve chamber preset inward bias on said resilient wall and when both said pilot valves are open the pressure in said pilot pressure chamber will float between the pressure in the outlet chamber and the pressure in the main valve operating chamber and the pressure in the main valve operating chamber will float between the inlet pressure and the outlet pressure to close said main valve when said inlet pressure is below the present inward bias on said resilient; wall whereby when said adjustable means biasing said resilient wall inwardly of said pilot pressure chamber is; preset to balance a desired main valve outlet pressure: in said pilot valve chamber and the main valve inlet pres--. sure is below said desired outlet pressure said first pilot; valve will be closed, the pressure in said main valve operating chamber and said main valve inlet chamber will; be the same and said main valve will be closed but when; said main valve inlet pressure rises above said desired out-- let pressure said inlet pressure acting through said orifice; said main valve operating chamber and said pilot valve; chamber to said pilot pressure chamber will overcome the biasing 'force on said resilient wall to open said first pilot; valve to relieve said main valve operating chamber pres-- sure to open said main valve and when said outlet pressure reacting on said pilot pressure chamber through said first pilot valve and said pilot valve chamber is greater than the bias effect of said adjustable means on said re silient wall said pilot valve stem and said resilient wall will close said second pilot valve to allow the pressure in. said main valve operating chamber to build up from said inlet chamber through said small orifice and close said main valve.

References Cited in the file of this patent UNITED STATES PATENTS 

